Organ procurement is the first step of organ preservation. We have developed "in situ machine wash out technique with CMH solution" for the purpose of rapid cooling and complete elimination of blood. The utility of this technique was confirmed by both experimentally and clinically. Two major techniques have been used for organ preservation. One is a simple cold storage. Using this method, it is easy to transport organs for transplantation. In addition, availability of UW solution is another advantage of this method. The other is a continuous hypothermic perfusion. Despite of complexity and difficulty of organ transportation, this technique has some advantages, such as viability assay and pretreatment of organs before transplantation. In our experimental studies, viability assays of canine liver and pancreas were achieved using a organ perfusion machine. We also succeeded to prolong the survival of canine pancreatic allograft by pretreatment of anti-Ia antibody during perfusion. While, cryopreservation is most suitable for cell preservation like pancreatic islets. Recently, gene technology was applied for organ preservation studies. In the future, this might become a potent tool for studies in this field.